I recently replaced the glass in a mobile home window using GE Silicone sealant II, retaining strips for the glass were totally oxidized, how ever the silicone dated use by 01/08 has not cured in two weeks. A trial sample from the same tube also does not cure after a week. Can I dig out the window’s sealant and reapply from another tube or will the residue “poison ” the new stuff?
Discussion Forum
Discussion Forum
Up Next
Video Shorts
Featured Story
![](https://images.finehomebuilding.com/app/uploads/2024/04/29113159/BUILDING-SCIENCE-SYMPOSIUM-1-Large-thumb-16x9.jpeg)
Check out the lineup for the 2024 Building Science Symposium featuring experts like Steve Baczek, Dr. Joe Lstiburek, and more.
Highlights
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Replies
You want to clean off the "old" stuff just as if you would cleaning off old cured caulk.
First I would work with rubbing alcholo. That will wash off "fresh" silicone caulk.
If that does not work then denatured.
After that I would clean it will a silicone caulk remover. I like LiftOff. Lowes has it by the paint removers and Goof Off.
Now that breaks down cured silicone and turns it slimy. So it only works on the surface and small amounts. You need to clean and scrap of the bulk first.
Then when everything is squeaky clean I would wipe it all down with the rubbint acholo before redoing.
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Your problem is really wierd. Silicones use a special polymer that is "capped" to prevent cure. Moisture in the air, etc, reacts with this cap and "opens" it allowing the silicone to then harden (by reacting with other polymers in the mixture.)
Most silicones become too hard and unusable, and that is why there is a Use By date on the product.
If yours isn't curing, and you don't live in a really (really, really, REALLY) dry climate, you should call the customer service number that is probably printed on the tube.
EDIT: I want to add that there are chemicals that can "poison" (that is, stop) the silicone cure. They might be on the window surface. To test this you should put a small amount on a piece of paper and see if it hardens. You should see this effect in a few hours. Just for fun, if it doesn't harden, sprinkle water on the stuff. If it hardens on the paper, there is something on the window/frame that is stopping the cure. You can try cleaning the area and see if that helps. Otherwise, you should consider another type of sealant.
Edited 8/22/2007 1:57 pm by JohnD1
Edited 8/22/2007 1:59 pm by JohnD1
Tried the bead on something else, also tried the water. St. Louis Area Summers are not noted for dryness
This came up maybe 9-12 months ago -- silicone caulk going bad such that it wouldn't cure. Several folks had the experience but I forget what the consensus was as to the cause. (Maybe stored in too hot of conditions?)
You nailed it... people left the tubes out in the heat and it went bad. Same complaint... "tube not expired, caulk won't cure."
I think you have identified the problem this area is in the grip of a heat wave, hasn't been this hot since the day I was born. Tube was in cab of the truck but not in direct sunlight. Thanks Rusty you have hit on the head
No problem. Here's someone else that suffered the horrible fate of having done a caulking job to find... yes, it didn't cure. And it was believed to be heat-related.
http://forums.taunton.com/tp-breaktime/messages?msg=78276.18
The thing that scares me is... so maybe I'm careful about storing the caulk in a cooler area. But what about it being stacked in boxes baking in the back of a trailer truck? Or in a hot area at the local lumberyard/Home Dumpster/Blowes? Yup... thoughts that make me happy...
made in China...contains nuclear waste.
C
Or maybe recalled toothpaste.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
Isn't everything made there? China isn't realy nuclar is it?
China successfully exploded its first atomic bomb on October 16, 1964.